The present invention relates generally to process control networks and, more specifically, to a device and method that enhances the documentation for process control systems using uniform resource locators.
Process control systems, such as those used in chemical, petroleum or other processes, generally include a centralized process controller communicatively coupled to one or more field devices which may be, for example, valve positioners, switches, sensors (such as temperature, pressure and flow rate sensors), etc. These field devices perform physical control functions within the process (such as opening or closing a valve), take measurements within the process for use in controlling the operation of the process or perform any other desired function within the process. Historically, process controllers have been connected to field devices via one or more analog lines or buses which may carry, for example, 4-20 mA (milliamp) signals to and from the field devices. Generally speaking, the process controller receives signals indicative of measurements made by one or more field devices and/or other information pertaining to the field devices, uses this information to implement a control routine and then generates control signals which are sent via the buses to the field devices to thereby control the operation of the process.
In the past decade or so, there has been a move within the process control industry to implement field-based digital communications within the process control environment. In fact, the process control industry has developed a number of standard, open, digital or combined digital and analog communication protocols such as the HART(copyright), PROFIBUS(copyright), WORLDFIP(copyright), Device-Net(copyright), CAN and FOUNDATION(trademark) Fieldbus (hereinafter xe2x80x9cFieldbusxe2x80x9d) protocols which generally enable more field devices to be connected to a particular bus, support more and faster communication between the field devices and the controller and/or allow field devices to send more and different types of information, such as information pertaining to the status and configuration of the field device itself, to the process controller. Furthermore, these standard digital protocols enable field devices made by different manufacturers to be used together within the same process control network.
With digital based control and communication, information pertaining to a device or an application (such as a software program) is typically made available to a user or operator in some standardized format within the control programming environment, i.e., within the protocol or software environment that actually implements control and/or communications within the process control network. For example, at least some of the above-identified communication protocols have specific fields for each process control element indicating the size of the element, the location of the element and a brief description of the element. However, the amount of memory or space provided for such information is typically very limited. In fact, in most cases, the description field for each process control element is limited to between 40 and 80 string characters. As a result, detailed documentation for process control elements is typically provided in a different environment, such as a word processing environment, which is more suitable for storing and displaying text documents having, for example, operating instructions, safety instructions, calibrating or trouble-shooting tips, etc. associated with each of the particular process control elements.
The description field related to each process control component within the control programming environment generally provides static text referring the user to the appropriate stand-alone documents in other programming environments. The user, upon viewing such information, must load the necessary software for viewing the stand-alone document and then must search for the document or otherwise call the document up to review the desired information for the process control element. This can be tedious and time consuming.
According to the present invention, uniform resource locators (URLs) are included in computerized documentation for a process control element, such as within the description field of a process control element, to provide an automatic link or connection to further documentation or a further application associated with the process control element. With URL(s) embedded into computerized documentation for a process control element, a user or an operator can automatically call related documentation or a related application for a process control element by merely selecting the URL(s).
Furthermore, a URL having a generalized field is embedded into computerized documentation for a process control element and, when selected, the generalized field is replaced with some information pertaining to the process control element, such as the name or location of the process control element or the name of a containing element (such as a process area or a node) of the process control element. In this manner, process control elements may be copied, renamed and changed without having to change the URL(s) provided in the documentation associated therewith.